The present invention pertains to an integrated oxygen fueled combustion and pollution control system. More particularly, the present invention pertains to an oxy-fueled combustion system having integrated pollution control to effectively reduce, to near zero, emissions from combustion sources.
Oxy-fueled combustion systems are known in the art. Such systems use essentially pure oxygen for combustion with fuel in near stoichiometric proportions and at high flame temperatures for high efficiency energy production. Oxy-fuel systems are used in boilers to produce steam for electrical generation and in industrial settings, such as in aluminum recycling to melt aluminum for recasting. It is also contemplated that oxy-fueled combustion can be used for waste incineration as well as other industrial and environmental applications. Oxy-fuel technology and uses for this technology are disclosed in Gross, U.S. Pat. Nos. 6,436,337, 6,596,220, 6,797,228 and 6,818,176, all of which are commonly owned with the present application and are incorporated herein by reference.
Advantageously, because oxy-fuel combustion uses oxygen rather than air as an oxygen source, there is concomitant reduction in flue gas produced. In addition, combustion is carried out so that the NOx combustion products are near zero and are due almost exclusively to fuel-borne nitrogen. That is, because oxygen rather than air is used as an oxygen source, there is less mass flow and no nitrogen to contribute to the formation of NOx.
Although oxy-fuel combustion provides fuel efficient and reduced emission energy generation, there is still a fairly substantial amount of emissions that are produced during the combustion process. In addition, because the volume of gas is less, due to the use of oxygen instead of air, the concentration of other pollutants is higher. For example, the mass of SOx and particulate matter will not change, however, the concentration will increase because of the reduced overall volume.
Pollution control or removal systems are known in the art. These systems can, for example, use intimate contact between the flue gases and downstream process equipment such as precipitators and scrubbers to remove particulate matter, sulfur containing compounds and mercury containing compounds. Other systems use serial compression stripping of pollutants to remove pollutants and recover energy from the flue gas stream. Such a system is disclosed in Ochs, U.S. Pat. No. 6,898,936, incorporated herein by reference.
Accordingly, there is a need for a combustion system that produces low flue gas volume with integrated pollution removal. Desirably, such a system takes advantage of known combustion and pollution control systems to provide fuel efficient energy production in conjunction with reduced pollutant production and capture of the remaining pollutants that are produced.